DETROIT — Why is it that whenever the Yankees wind up a season with an embarrassing loss at Comerica Park, Alex Rodriguez’s future becomes the No. 1 conversation topic?

Probably just coincidence. Nevertheless, just as we stood here six years ago and watched the Tigers steamroll over the Yankees and a former Indians ace (remember Jaret Wright?) in the American League Division Series clincher, the Tigers dominated the Yankees and former Indians ace CC Sabathia yesterday, 8-1, to complete an AL Championship Series four-game sweep and advance to the World Series.

Just as we did then, we’re left wondering, more than anything else, what happens now with Rodriguez. Except that A-Rod, who controls his own destiny because he must green-light any trade, said yesterday there’s nothing to discuss.

“That’s right. I will be back,” the 37-year-old said after the game. “I have a lot to prove, and I’ll come back on a mission.”

Do we believe him? I’m inclined to, yes. Because it’s going to be highly difficult for the Yankees to find an A-Rod trade that is less than completely odious, given the five years and $114 million remaining on his contract and his October vanishing. And because Rodriguez is highly mindful of his legacy, and how it would look for him to skip town now, after the lowest point in his nine years as a Yankee?

“I sat in this room in 2006. Some of you guys were here,” Rodriguez told a group of reporters. “There [were] a lot of doubters. I said I was going to get back to the drawing board, and I came back with a vengeance in ’07. I’m looking forward to hopefully doing the same.”

It was Game 4 of the ’06 AL Division Series when Joe Torre tried hitting Rodriguez eighth. A-Rod went 0-for-3 and Wright and the Yankees lost, 8-3, immediately raising questions about their top diva. Armed with a no-trade clause, A-Rod quickly squashed such talk, and after winning the 2007 AL Most Valuable Player award, he opted out of his contract and worked Yankees ownership for the 10-year, $275-million albatross that is now officially halfway finished.

Five straight years of decline later, Rodriguez turned into a part-time player this postseason. Yesterday marked his third benching of the postseason, and in three other games, he started, only to be lifted for a pinch hitter. He finished this playoff run with three hits in 25 at-bats, a .120 batting average, and 12 strikeouts. Since his magical 2009 run to the Yankees’ World Series title, A-Rod has 12 hits in 75 postseason at-bats, a .160 batting average, and 24 strikeouts. Among those 12 hits are two doubles, no triples and no homers.

A day after talking around a question about Joe Girardi’s lineup maneuvers, sending off signals of his unhappiness, A-Rod performed damage control on that front.

“The thing is, about this whole situation, if I’m playing my game, Joe has no choice but to play me,” Rodriguez said. “If I’m not playing my game, then he’s looking for options. I’ve got to look in the mirror.”

Rodriguez added that he didn’t feel a meeting with Girardi, general manager Brian Cashman or anyone else was necessary.

Said Girardi of his relationship with A-Rod: “As far as I know, we’re OK. It’s not something I wanted to do. … You know that. But I don’t have any signals that he’s mad at me. I know he wanted to be in there. I understand that.”

Cashman said: “I expect Alex to be back [next year],” and he added, “Despite being not the Alex Rodriguez of years past, he’s still above average at that position. That’s it. … Is there more? Absolutely.”

Agreed that Rodriguez still provides some value, but can he get better? His OPS has decreased every single year from 2008 onward; it slipped to .783 in 2012. Staying on the field has proven a significant challenge for him.

“I’ve never thought about going to another team,” Rodriguez said. “My focus is still here. Let’s make that very, very clear. Number two, I don’t expect to be mediocre. I expect to do what I’ve done for a long time.”

What he’s done recently isn’t too great, but reckless spenders can’t be choosers. So barring the Miami Marlins losing their minds and agreeing to take on a huge chunk of Rodriguez’s contract, buckle up and expect consistent drama and inconsistent production, and check in again a year from now. This is a marriage we’ll always be scrutinizing until it finally ends.